Alright so

2010 LNF, had a zzp tune and broke the intercooler.

Just got the intercooler swapped in, new charge pipes too. (Also ZZP intake and catted DP)

the car idles fine, holds 14.7 on the AFR gauge, but when I start driving it it goes absolutely crazy.

I will get a video later, but the gauge seems to just randomly move off throttle, with some throttle it balances out around 13-15 but still nowhere near as stable as before. When off throttle, in gear or in neutral, it wildly moves from 10-18, even below 2200 rpm or whatever the stock fuel shutoff is.

when coasting in neutral, the car idles around 900 rpm but fluctuates up and down 200-500 rpm due to the AFR’s, but when stopped and neutral idling it idles just fine around 14.0-15.0.

only thing I can think of is the Primary O2 sensor, but I can’t believe it would cause it to move this sporadically, also unplugged the evap solenoid on the intake, made no difference.

new Maf sensor, no boost leaks, stock tune stock Map sensors

thanks for your help, video will be posted soon

 

 

Car isnt showing any CEL, Have cleared the codes within the last 50Km so maybe it never re-checked for codes or whatever

 

With the ZZP tune did you get an update for your car specifically? What I'm wondering happened was you had a small boost leak that is accounted for in the tune, now that you've replaced everything it's no longer there.

Now for other potential causes, is the pcv line to the intake in good shape and not broken? You mentioned no boost leaks, I'm assuming you've done a boost leak test to confirm the no boost leaks and not just a visual inspection.

 

I'm going to go buy the parts to build a tester tomorrow, but the pipes are freshly installed and all connections and clamps checked to be tight as possible, I guess there could possibly be a small leak somewhere. Would a small leak cause it to sway that far out of Acceptable AFR?

Those videos are on the stock file with stock MAP Sensors. The ZZP tune is just a tuned PCM they shipped to me, I do not have HP Tuners yet, but seems like I need to get it.
With Intake, Downpipe, and ZZP tune, the car ran fine and with good AFR, Then the intercooler end tank exploded during a pull. Had to unplug the MAF to be able to drive it 10 mins to get home, and the AFR's were doing the same at that time as they are now.
Now I have the intercooler in, Stock Tune, Stock MAP Sensors and a Fresh MAF, and its still doing this.

The PCV line is in good condition, It does not have the plastic piece however anymore, as the zzp kit deletes it. Just a straight line into the silicone intake tube.

Not sure if its super important, But I notice the fuel pressure fluctuating with the AFR quite a bit at idle in video #2.

Thanks again

 

Is it possible that driving it home with the maf unplugged and a massive hole in the intercooler, messed up the tune enough to have it still run like trash?

just brainstorming, wouldn’t make sense anyways because I swapped between tuned and stock PCM’s and still had the same issue

 

Generally on any car when you clear the codes it resets all the learned values like st/lt fuel trims, so it may take a few for the car to relearn that. As to the actual issue, I'm leaning the same way as ECaulk with there possibly being an air leak still or the tune accounted for a minor leak before. It's possible the upstream o2 sensor is smoked, but a bit odd since I don't see driving 10mi being enough to destroy it.

 

One other thing, before the intercooler broke, the car was at 14.7 pretty much at all times, and went full lean when downshifting above 2200 RPM, as it’s supposed to.

but now, it will go lean when off throttle, and stay lean until either I blip the gas, or push the clutch in, no matter the RPM

by going lean, I mean the RPD is pegged at 18 the entire time, even through 2000-1400 rpm

i will build a boost leak tester in tomorrow and see what I can find. Maybe I will disconnect battery aswell to fully reset the stock tune file.

 

The boost leak is the place to start.

Disconnecting the battery will only reset fuel trims, not reset the tune. If you have hptuners and switch the tune back to the stock tune (granted an intake will impact fuel trims) then you can quickly find out if the swings are software or hardware related.

 

I literally took the tuned PCM out, put the stock one in, and still had the exact same issue, which is why I don’t think it’s tune related at all. It also was fine until the IC blew apart, that’s where this problem started I guess.

 

Well, then everything is pointing towards a leak or sensor issue.

Do you have a stock intake still? Some intakes run funky trims on the stock tune.

 

I do not, I don’t think the intake is causing it as the AFR’s were normal for 2 weeks before intercooler blew, and then this problem started.

just had to start it to move it away from my garage. Blipped the throttle to 2000rpm a couple times, it would go to 13 on the way up the revs, then jump back to 16-18 on the way down, Fuel pressure isn’t steady at idle either, but I’m not sure how stable it’s supposed to be.

I will make a trip tomorrow to get the parts to Build a Tester and will let you know my results tomorrow or Sunday.

thanks so much for your help!

 

The trims wouldn't be funky on the tuned ecu, just with the stock ecu.

Seeing the fuel trims go to 13 and then drop to 16-18 during a blip isn't surprising and I would assume the car was in open loop so no fuel trim correction was occurring beyond the LTFT as that's global.

Also, the fuel pressure isn't steady at idle it does fluctuate so that normally isn't a huge concern.

 

I’ll check for leaks and maybe put the other tune file back in. What is open loop?

 

This is exactly what you need to do. Getting the PCM shipped from ZZP is basically a file that is made to suit your mods. To dial in your tune more you would send logs to ZZP and get the tune revised so it relates to your cars health. Or get a different tuner.

 

Went to get parts to make a boost leak tester and they had nothing even close to what I need, so I will have to do some more work to make one, also ordered a new O2 sensor, just gotta wait for it.

This is a video right after a cold start.

 

Did you ever find a solution for this issue?